jdoughertyii/PyVCF — pull request #8 by myourshaw (2014-12-19 20:14:41+00:00)
Title: ID field as semicolon-separated list

From the VCF spec: "ID - identifier: **Semi-colon separated list** of unique identifiers where available. If this is a dbSNP variant it is encouraged to use the rs number(s). No identifier should be present in more than one data record. If there is no identifier available, then the missing value should be used. (String, no white-space or semi-colons permitted)"